Currently commercially available bicycle pumps are intended to be rugged, lightweight, easy to manufacture and repair, simple to operate and relatively efficient. Exemplary of the currently available bicycle pumps are those which use the construction illustrated in U.S. Pat. No. 3,981,625 which issued on Sept. 21, 1976 to Wickenberg. In that arrangement the piston head is formed with a specially-designed and shaped annular seal having a V-shaped cross section. Since that seal forms an integral dynamic part of the piston construction and is in constant movement when in use, it tends to wear. Unfortunately, because it is specially shaped, it is not easily replaced. Consequently, on wearing of that particular component the pump may become virtually useless. Thus, the unavailability of a replacement component at a relatively low cost and from an easily-accessible source limits the overall utility and worth of the pump. In addition, the special shape of these members subject them to increased manufacturing cost.
There are a number of other patents that have issued relating to valve constructions for pumps, which have a variety of limitations, that make the valve designs unsuited for current commercial pumps, and in particular unsuited for bicycle pumps. These patents include U.S. Patent No. 1,192,509 which issued July 25, 1916 to Feeny; U.S. Pat. No. 2,683,060 which issued July 6, 1954 to Wise; U.S. Pat. No. 654,706 which issued July 31, 1900 to Braymer; U.S. Pat. No. 3,329,068 which issued July 4, 1967 to Klaus and U.S. Pat. No. 3,190,2666 which issued June 22, 1965 to Malec. While not all of these disclose hand pumps primarily designed for bicycles, they all disclose valve constructions of various designs. None of these valve constructions, however, appear to be more-relevant than U.S. Pat. No. 3,981,625 referred to above.